from axl.axel import Event
from couchpotato.core.helpers.variable import mergeDicts, natcmp
from couchpotato.core.logger import CPLog
import threading
import traceback

log = CPLog(__name__)
events = {}

def runHandler(name, handler, *args, **kwargs):
    try:
        return handler(*args, **kwargs)
    except:
        from couchpotato.environment import Env
        log.error('Error in event "%s", that wasn\'t caught: %s%s', (name, traceback.format_exc(), Env.all() if not Env.get('dev') else ''))

def addEvent(name, handler, priority = 100):

    if events.get(name):
        e = events[name]
    else:
        e = events[name] = Event(name = name, threads = 10, exc_info = True, traceback = True, lock = threading.RLock())

    def createHandle(*args, **kwargs):

        try:
            parent = handler.im_self
            bc = hasattr(parent, 'beforeCall')
            if bc: parent.beforeCall(handler)
            h = runHandler(name, handler, *args, **kwargs)
            ac = hasattr(parent, 'afterCall')
            if ac: parent.afterCall(handler)
        except:
            h = runHandler(name, handler, *args, **kwargs)

        return h

    e.handle(createHandle, priority = priority)

def removeEvent(name, handler):
    e = events[name]
    e -= handler

def fireEvent(name, *args, **kwargs):
    if not events.get(name): return
    #log.debug('Firing event %s', name)
    try:

        options = {
            'is_after_event': False, # Fire after event
            'on_complete': False, # onComplete event
            'single': False, # Return single handler
            'merge': False, # Merge items
            'in_order': False, # Fire them in specific order, waits for the other to finish
        }

        # Do options
        for x in options:
            try:
                val = kwargs[x]
                del kwargs[x]
                options[x] = val
            except: pass

        e = events[name]

        # Lock this event
        e.lock.acquire()

        e.asynchronous = False

        # Make sure only 1 event is fired at a time when order is wanted
        kwargs['event_order_lock'] = threading.RLock() if options['in_order'] or options['single'] else None
        kwargs['event_return_on_result'] = options['single']

        # Fire
        result = e(*args, **kwargs)

        # Release lock for this event
        e.lock.release()

        if options['single'] and not options['merge']:
            results = None

            # Loop over results, stop when first not None result is found.
            for r_key in sorted(result.iterkeys(), cmp = natcmp):
                r = result[r_key]
                if r[0] is True and r[1] is not None:
                    results = r[1]
                    break
                elif r[1]:
                    errorHandler(r[1])
                else:
                    log.debug('Assume disabled eventhandler for: %s', name)

        else:
            results = []
            for r_key in sorted(result.iterkeys(), cmp = natcmp):
                r = result[r_key]
                if r[0] == True and r[1]:
                    results.append(r[1])
                elif r[1]:
                    errorHandler(r[1])

            # Merge
            if options['merge'] and len(results) > 0:
                # Dict
                if isinstance(results[0], dict):
                    merged = {}
                    for result in results:
                        merged = mergeDicts(merged, result)

                    results = merged
                # Lists
                elif isinstance(results[0], list):
                    merged = []
                    for result in results:
                        merged += result

                    results = merged

        modified_results = fireEvent('result.modify.%s' % name, results, single = True)
        if modified_results:
            log.debug('Return modified results for %s', name)
            results = modified_results

        if not options['is_after_event']:
            fireEvent('%s.after' % name, is_after_event = True)

        if options['on_complete']:
            options['on_complete']()

        return results
    except KeyError, e:
        pass
    except Exception:
        log.error('%s: %s', (name, traceback.format_exc()))

def fireEventAsync(*args, **kwargs):
    try:
        my_thread = threading.Thread(target = fireEvent, args = args, kwargs = kwargs)
        my_thread.setDaemon(True)
        my_thread.start()
        return True
    except Exception, e:
        log.error('%s: %s', (args[0], e))

def errorHandler(error):
    etype, value, tb = error
    log.error(''.join(traceback.format_exception(etype, value, tb)))

def getEvent(name):
    return events[name]